In the lawsuit filed in California’s Santa Clara County on Wednesday, the San Jose-based company claims that Amazon had “perpetrated a scheme to infiltrate and exploit eBay’s internal member email system” over the past three years.

“Amazon did this to recruit high-value eBay sellers,” the lawsuit reads. “Since 2015, dozens of Amazon sales representatives in the U.S. and overseas set up eBay member accounts to access eBay’s ‘M2M’ email system and used that system to solicit many hundreds of eBay sellers to sell on Amazon’s platform.”

(M2M is eBay’s member-to-member messaging system, allowing sellers to communicate with one another as well as customers and the company itself.)

A few weeks ago, upon learning about the e-tail giant’s alleged efforts to lure its marketplace sellers, eBay sent a cease-and-desist letter urging Amazon to halt such supposed activity.

It accused the latter of conducting an “orchestrated, coordinated, worldwide campaign,” adding that Amazon representatives allegedly sought to avoid detection by asking sellers to move their discussions off the M2M system and using variations of its name such as “a-m-a-z-o-n” and “AMZ.”

Citing an alleged example, the company claimed that representatives from Amazon said, “eBay does scan for key terms, and they don’t exactly like us poking around. Honestly the easiest way to communicate about this would be on the phone.”

In the claim, eBay asks for monetary relief in unspecified damages as well as to permanently enjoin Amazon from improperly using its messaging system.

Amazon declined to comment, while eBay said it was not commenting beyond what was already filed in the lawsuit.